1 IP address is located in the guest network

You cannot set up port sharing in the FRITZ!Box for devices that are connected to it via the LAN or wireless guest network. The FRITZ!Box does not allow devices in the guest network (IP network 192.168.189.0, subnet mask 255.255.255.0) to be accessed from the Internet.

2 IP address is located in another IP network (subnet)

Due to an error in FRITZ!OS, you cannot set up port sharing for devices that are in a downstream IP network (subnet), for example in the IP network of an additional router connected to the FRITZ!Box.

We are currently working on a solution and shall correct this behavior with a FRITZ!OS update for the FRITZ!Box as soon as possible. We cannot give you an exact release date for the update yet.

Note:You can have the push service notify you by e-mail when new updates are available. In addition, you can configure the FRITZ!Box so that new updates are installed automatically. You can enable these options under "System > Push Service" or "System > Update > Auto Update" in the user interface.

3 Multiple IP addresses for the same MAC address

You cannot set up port sharing in the FRITZ!Box for devices if they use multiple IP addresses for the same MAC address. Currently, the FRITZ!Box does not support devices that use several IP addresses with the same MAC address (for example virtual machines with manually assigned MAC addresses that are used by several devices in the home network).